Process for making printing plates and light sensitive material for use therein



United States Patent 3,046,123 PROCESS FGR MAKING PRINTING PLATES ANDLIGHT SENSITIVE MATERIAL FOR USE THEREIN Oskar Siis, Wilhelm Neugebauer,and Maximilian Paul Schmidt, Wiesbaden-Biebrich, Germany, assignors, bymesne assignments, to Azoplate Corporation, Murray Hill, NJ.

No Drawing. Original application June 21, 1955, Ser. N 517,086. Dividedand this application Mar. 3, 1958, Ser. No. 718,477 Claims priority,application Germany Dec. 14, 1951 52 Claims. (Cl. 96-33) The presentinvention relates to the production of light-sensitive material suitablefor use in the graphic art. More particularly, it relates to aphotomechanical method for the manufacture of printing plates and tolight-sensitive material suitable for use in the said method.

In the US. patent application Serial No. 174,556, filed on July 18,1950, by Maximilian Paul Schmidt, and now abandoned a process isdescribed for producing printing plates by means of diazo compounds.According to this process diazo compounds that are constitutionallyesters or amides of sulfo acids or carboxylic acids of2-diazonaphthol-(l) or of l-diazo-naphthol-(Z) are used to produce alight-sensitive layer on a base material. This layer is then exposed tolight through a pattern, treated with alkali and heated. In saidapplication it has also been shown that modifications of the procedureare possible by providing for the addition of alkali-soluble resins orfatty acids to the light-sensitive layer and by dispensing with theheating subsequent to the development of the exposed layer.

The US. patent applications Serial No. 238,369, filed on July 24, 1951,by Oskar S is, and Serial No. 268,148, filed on January 24, 1952, byOskar Siis and Maximilian Paul Schmidt, both now abandoned, show thatother orthoquinone diazides in the form or" their sulfo-acid orcarboxylic acid esters or amides, respectively are well suited for useas light-sensitive diazo compounds.

It has now been found that excellent results are obtained according tothe processes disclosed in the patent applications referred to above bythe use, as light-sensitive substances, of the sulfo acid amides oforthoquinone diazides conforming to the general formula organicsolvents, such as, for example, ethylene glycol monomethyl ether,dioxane and dimethyl-formamide, but are insoluble in cold water, thusmaking it possible to apply the light-sensitive substance uniformly tothe base material and to provide layers that are not sensitive tomoisture and, in "consequence, are of good durability.

Suitable base materials for the light-sensitive layer are paper thesurface of which may have undergone a special pretreatment, and metals,such as, for example, aluminum or zinc. The diazo compounds are applied,in a known manner as by whirl-coating, brushing, or spraying solu-3,046,123 Patented July 24, 1962 tions of the compounds in organicsolvents. Solvents having boiling points within the range of from 70 C.to C. are preferred. The solvent is evaporated by thoroughly drying thelight-sensitive layers. The addition of alkali-soluble resins to thesensitizing solutions frequently proves advantageous for the formationof a uniform film-like coat. Also said resins tend to prevent theformation of centres of crystallization which cause the layer to break.Furthermore, the addition of resins improves the adhesiveness of thelayer to the base Illaterial. It is possible also to prevent theformation of crystals on the surface of the layer by employing mixturesof two or more diazo compounds.

Images are produced on the light-sensitive material in the well-knownmanner by exposing the layer side of the material to light through atransparent pattern. Depending on the color of the diazo compound used,an image is produced that is more or less clearly visible. The diazocompound remains unchanged at the places not alfected by light, while itis decomposed at the places exposed to light. In most cases thelight-decomposition products are colorless. Sometime, however, a slightcoloring appears in the background of the image as a result of secondaryreactions of the light-decomposition product.

Whenever it is intended to use the layer bases as printing plates, it isnecessary to develop the produced image by removing thelight-decomposition product, because the light-decomposition product isjust as oleophilic as the non-decomposed diazo compound and would retaingreasy ink as does the diazo compound. The image is developed bytreating the exposed material with weak alkalies. The diazo compound isinsoluble or not readily soluble in weak alkalies whereas thelight-decomposition product is removed. The diflerent behaviour of thelight-decomposition product and the undecomposed diazo compound withweak alkalies is explainable by the fact that under the influence oflight compounds containing carboxyl groups are formed from the diazocompound. (0. S ils, Justus Liebigs Annalen der Chemie, volume 556(1944), pages 65 if.) It is readily understood, therefore, that diazocompounds best suited for the development of the image are those inwhich the acyl group linked to the nitrogen atom of the acid amide groupcontains a quinone diazide residue. The light-decomposition products ofsuch diazo compounds contain several carboxyl groups and the selectiveseparation from the diazo compound is considerably facilitated when theexposed layer is treated with diluted alkalies.

Many of these diazo compounds after exposure can be developed by meansof organic solvents for the purpose of making positive printing platesfrom negative patterns and vice versa.

In most cases the image shows a greenish-yellow color after beingdeveloped. In practice, it is desirable to ob tain images that are asdeeply colored and as rich in contrast as possible, whereby the progressof the image formation may be readily observed. Variation of the acylresidues linked to the nitrogen atom of the sulfonamide group mayproduce a deeper color shade of the respective diazo compounds. By usingdiazo compounds that show a stronger coloring, it is possible to producelayers that yield images ranging in color from brownish-yellow tobrownish-red. In many cases slight heating of the solutions of the diazocompound, and in particular diazo compounds that contain at least oneo-quinone-diazide residue belonging to the benzene series, makes itpossible to obtain deeply brownish-yellow colored layers and images. Itis possible also to greatly influence the color shades of the finishedimages by adding suitable dyes to the sensitizing solution.

duced, for example, by reaction of either carboxylic acid chlorides orsulfonic acid chlorides with sodium salts of the sulfonamides, of theorthoquinone diazides. These sulfonamides, which are used as startingmaterial, are obtained by causing primary organic bases to react withthe chlorides of the orthoquinone-diazide sulfonic acids.

The diazo compounds to be used according to the invention may also beobtained by the condensation of orthoquinone diazide sulfochlorides withacylated primary bases.

The compounds shown below are referred to in the following exampleswhich illustrate the present invention:

Formula 1 II N Na: =N2

s01Ns Formula 2 0 0 II II w w S07--N SO:

Formula 3 0 H II N}: Nz

SOr-N-SO;

Formula 4 Formula 5 Formula 6 Formula 7 0 ll w Q Formula 8 I TSOgFormula 9 I SO 2 Formula Formula 11 O O I] ll W Formula 12 Formula 13Formula 1 4 O 0 ll H W I I 6 Formula 15 Formula 16 C Ha Formula 17 ClCH3 l Formula 18 Formula 19 The following examples are included merelyfor the purpose of illustrating the above described process without anyintention of restricting the scope of the invention.

(1) One part by Weight of the diazo compound corresponding to Formula 1in the above table is dissolved in one hundred parts by volume ofethylene glycol mono methyl ether, and this solution is applied bywhirlcoating to an anodically oxidized aluminum foil. The coated side ofthe foil is dried in a Warm aircurrent, and drying of the foil is thencontinued for about five minutes in a drying chamber at a temperature of90 C. The sensitized material is exposed for three minutes to thelightrays emitted by an arc lamp (18 amperes, distance from the lampabout 70 cm.) behind a transparent positive pattern. Agreenish-yelloW-colored positive image of the pattern is obtained and isdeveloped by wiping the image side of the exposed foil with a 1%solution of trisodium phosphate. The foil is then rinsed with water andsubsequently treated with an aqueous solution containing 8% dextrin, 1%phosphoric acid, and 1% formaldehyde. The image can now be inked Withgreasy ink and used for printing.

The diazo compound conforming to No. 1 in the table may be prepared inthe following manner:

Two mols of aniline and one mol of naphthoquinone-(1,2)-diazide-(2)-5-sulfochloride, dissolved in dioxane,

form naphthoquinone (1,2) diazide (2) 5 sulfanilide which, afterrecrystallization from glacial acetic acid melts at 160 C. underdecomposition. 16 parts by weight of the sulfanilide (one mol) aredissolved in 200 parts by volume of dioxane and are converted into thesodium salt by the addition of 62 parts by volume of n-sodalye(approximately 1.2 mols). The thus obtained alkaline reactingbrownish-yellow solution is immediately mixed with a solution of 16parts by weight of naphthoquinone-( 1,2) -diazide- 2 -5-sulfochloride(approximately 1.2 mols) in 100 parts by volume of dioxane. After thismixture has stood for about two days, the N,N-di- (naphthoquinone (1,2)diazide (2) 5 sulfonyl)- aniline precipitates in the form of largeyellow crystals. This diazo compound is separated, reduced to a finepowder in a weak aqueous solution of caustic soda, separated anew, andis washed with water. When heated rapidly in a capillary tube, thecompound decomposes at a temperature of about 145 C., withoutappreciably changing its color.

(2) In the process described in Example 1 above, the diazo compound ofFormula 2 may be used in the place of the diazo compound of Formula 1with equal success. The diazo compound of Formula 2 is applied to thealuminum foil by whirlcoating a 1% solution of the diazo compound indioxane, said solution containing 0.2%

I'OSlIl.

The diazo compound conforming to No. 2 in the table may be prepared fromnaphthoquinone-(1,2)-diazide-(2)- 4-sulfochloride and aniline in amanner analogous to that described above for preparation of the diazocompound used in Example 1. The intermediary product, naphthoquinone-(1,2)-diazide-(2)-4-sulfanilide, decomposes at a temperature of129 C. In preparing the bis-sulfonyl compound from this intermediaryproduct it is desirable to employ a somewhat larger excess (1.5 times)of the naphthoquinone-(1,2)-diazide-(2)-4-suliochloride as well as ofthe soda solution as acid-binding agent. N,N di (naphthoquinone (1,2)diazide (2) 4 sulfonyl) aniline starts to decompose slowly, when heatedin a capillary tube at a temperature of 130 C. and detonates-at 155 C.while darkening.

(3) 1 part by weight of the diazo compound corresponding to Formula 3 isdissolved in 100 parts by volume of ethylene glycol-monomethyl ether,and this solution is used for coating an aluminum foil one side of whichhas been roughened mechanically. The thoroughly dried light-sensitivefoil is used to produce an image as described in Example 1. The exposedside of the foil is brushed with a 1% solution of trisodium phosphate,briefly rinsed with water, and then treated with a 1% solution ofphosphoric acid. In this case also, a positive image, which can be inkedand then be used as a printing plate, is obtained from a positivepattern.

For preparing the diazo compound of the Formula 3 one mol ofnaphthoquinone-(1,2)-diazide-(2)-5-sulfochloride and two mols ofmonomethylamine are converted in dioxane intonaphthoquinone-(1,2)-diazide-(2)-5-(N- methyl)-sulfonamide whichdecomposes at a temperature of 154 C. subsequent to itsrecrystallization from glacial acetic acid. The thus obtainedsulfonamide is condensed with one more molecule of naphthoquinone-( 1,2)-diazide- (2)-5-sulfochloride in the presence of a normal solution ofcaustic soda yielding N,N-di-(naphthoquinone-(1,2)-diazide-(2)-5-sulfonyl)-methyl-amine. The procedure followed isanalogous to that used for the preparation of the diazo compound ofFormula 1. On heating the diazo compound of the Formula 3 in a capillarytube, the compound starts to darken at a temperature of 130 C. and charsmore and more when the heating to higher temperatures is contained.

(4) In the same manner as described in Example 3, an aluminum foil iscoated with a 1% solution of the diazo compound corresponding to Formula4 in methyl-ethylketone containing an addition of 0.2% of rosin. Theimage produced by the exposure of the coated foil under a positivepattern is developed as explained in Example 3 and can be used as apositive printing plate.

The diazo compound corresponding with Formula 4 is obtained by thecondensation of naphthoquinone-(l,2)- diazide-(2)-5-sulfanilide withp-toluene-sulfochloride following the method indicated for thepreparation of the diazo compound of Formula 1. On heating theN-ptoluene sulfonyl N (naphthoquinone (1,2) diazide- (2) 5 sulfonyl)aniline for the purpose of determining its melting point, slowdecomposition of the compound sets in at a temperature of 150 C. Furtherheating up to a temperature of about 190 C. leads to a tough blackmolten mass.

(5) A superficially roughened zinc plate is brushed for five minuteswith a solution of 4 parts by weight of potassium-aluminum-sulfate inparts by volume of a 4% solution of acetic acid. The plate is thenrinsed with water, dried, and finally coated on a plate-whirler with a1% solution of the diazo compound corresponding to Formula 5 in ethyleneglycol-monomethyl ether. After exposing the sensitized plate under apositive pattern, the greenish-yellow-colored positive image isdeveloped with a 2% solution of trisodium phosphate and is then brieflywiped over with a 5% solution of acid salts of the kind described, forinstance, by Strecker in the German Patent No. 642,782. Finally, theimage is inked with greasy ink.

In order to prepare the diazo compound corresponding to Formula 5,equimolecular quantities of naphthoquinone-(1,2)-diazide-(2)-5-sulfochloride and of a-naphthylamine arecondensed in dioxane, to which pyridine is added as ahydrochloric-acid-binding agent. The naphthoquinone (1,2) diazide (2) 5N 0c naphthyl sulfonamide thus obtained decomposes, when recrystallizedfrom glacial acetic acid, at a temperature of C. It is converted withanother molecule of naphthoquinone- (1,2)-diazide-(2)-5-sulfochloride,analogously to the procedure described in Example 1, intoN,N-di-(naphtho quinone (1,2) diazide (2) 5 sulfonyl) oz naphthylaminewhich decomposes, when rapidly heated in a capillary tube, at atemperature of about C. without any material change of color.

(6) The casein-containing layer side of a paper foil, produced inaccordance with U.S. Patent No. 2,534,588 and coated on one side with alayer comprising casein and clay and hardened by means of formaldehyde,is coated by brushing with the solution of 1 part by weight of the diazocompound corresponding to Formula 6 in 100 parts by volume of ethyleneglycol-monomethyl ether. After the light-sensitive layer has been dried,the foil is exposed to light under a transparent positive pattern, andthe image thus obtained is developed with a 1% solution of trisodiumphosphate. This image is yellow-orangecolored on a practically whitebackground. This image, which is positive with respect to the pattern,is wiped over with a solution containing ammonium phosphate, glycerin,and phosphoric acid, and can be used as a printing plate after beinginked with greasy ink.

The diazo compound corresponding to Formula 6 is obtained by thecondensation of naphthoquinone-(1,2)- diazide-(2) 5 sulfanilide withbenzoquinone (1,2)- diazide-(2)-4-sulfochloride analogously to themethod indicated for the production of the diazo compound correspondingto Formula 1. The N-[benzoquinone-(1,2)- diazide (2) 4 sulfonyl] N[naphthoquinone (1,2) diazide (2) 5 sulfonyl] aniline decomposes at atemperature of 148 C. after changing to red in color.

(7) 0.8 part by weight of the diazo compound corresponding to Formula 7,0.08 part by weight of l benzene-azo-Z-hydroxy-3-naphthoic acid, and0.16 part by weight of a formaldehyde phenol-novolak are dissolved in100 parts by volume of ethylene glycol-monomethyl ether. Theformaldehyde-phenol-novolak is sold, for instance, by the firm ChemischeWerke Albert at Wiesbaden-Biebrich under the commercial name Alnovol(registered trademark in Germany). This solution is used for coating amechanically roughened aluminum foil. After drying, the coated foil isexposed to light under a positive pattern as described in Example 1, anda violet-red-colored positive image is developed by dabbing the exposedlayer with a 2% solution of trisodium phosphate. The background of theimage is then cleaned by a treatment with a solution containing 8% ofdextrin, 1% of phosphoric acid, and 1% of formaldehyde.

The diazo compound corresponding to Formula 7 is prepared, analogouslyto the procedure described in the previous examples, by causingnaphthoquinone-(1,2)- diazide-(2)-5-sulfanilide to react with benzoylchloride. When heated, the N-benzoyl-N-[naphthoquinone-(1,2)-diazide-(Z)-5-sulfonyl]-aniline first takes on a brown color andafterwards decomposes at a temperature of 170 C.

(8) 1.5 parts by weight of the diazo compound corresponding to Formula8, being the condensation product ofnaphthoquinone-(1,2)-diazide-(2)-5-sulfochloride and 1,8-naphthsultam,are dissolved in 100 parts by volume of ethylene glycol-monomethylether. This solution is applied in the customary manner as a thin layerto a mechanically roughened aluminum foil. After drying, the layer isexposed to light under a transparent positive pattern, and theindistinctly visible yellow image is developed with a 3% solution oftrisodium phosphate. Following development, the foil is rinsed withwater and wiped over with a diluted solution of phosphoric acid. Whenthe stable positive image thus obtained is inked with greasy ink, it ispossible to use it for printing copies in the customary manner. Thecondensation product corresponding to Formula 8 is obtained in thefollowing manner:

2 parts by weight of 1,8-naphthsultam are dissolved in 15 parts byvolume of dioxane. To this solution there are added 2.7 parts by weightof naphthoquinone(1,2)- diazide-(2)-5-sulfochloride in approximately 12parts by volume of dioxane and 5 parts by volume of water. Then 16 partsby volume of a 10% solution of soda are added dropwise into the reactionmixture at a temperature of 40-50 C., while agitating the reactionmixture. A yellow product gradually separates, the quantity of which isincreased by addition of 50 par-ts by volume of water into the reactionvessel at the end of the reaction. Subsequent to cooling, the separatedcondensation product is isolated by means of a suction filter and iswashed neutral with water. It is dried and recrystallized from benzeneto which a little dioxane has been added. When heated, the compoundbegins sinten'ng at a temperature of approximately 210 C. and decomposesat from 225 C. to 230 C.

(9) The condensation product corresponding to Formula 9, which is thereaction product of naphthoquinone- (1,2)-diazide-(2)-5-sulfochlorideand p-toluene-sulfonefi-naphthylamide, can be used in a similar mannerfor producing images and printing plates. It is produced by adding to asolution of 2.9 parts by Weight of p-toluenesulfone-fl-naphthyl amide in20 parts by volume of dioxane 2.7 parts by weight ofnaphthoquinone-(1,2)-diazide- (2)-5-sulfochloride in 12 parts by volumeof dioxane. 12 parts by volume of a 10% solution of soda are addeddropwise while the reaction mixture is heated to a temperature of 50 C.The condensation is completed in approximately half an hour. Then themixture is poured into approximately 300 parts by volume of Water, and10 parts by volume of a 10% solution of caustic soda are added. Thecondensation product thus precipitated is filtered off by suction and iswashed neutral with water. Subsequent to drying at a temperature of 50C. it consti- CAD tutes a yellow powder that is insoluble in acids anddiluted alkalies. For purification the raw product is dissolved inbenzene, and the solution is treated with animal charcoal. Afterfiltering the solution, gasoline is added whereupon the new diazocompound N p-toluenesulfonyl N [naphthoquinone (1,2) diazide (2)S-sulfonyl]-p-naphthylamine separates. It is filtered and dried. Onheating the new compound, decompostiion begins at a temperature of 190C. In the presence of soda lye and a solvent the condensation productcouples with phloroglucinol to form a violet dye which turns orange onaddition of acids.

(10) 1 part by weight of the diazo compound corresponding to Formula 10is dissolved in parts by volume of dimethyl-formamide. This solution isused for coating an aluminum foil in the customary manner. An image of apattern is produced on the thoroughly dried foil in the customary mannerand developed by means of a 5% solution of disodium phosphate. Thepositive image thus obtained is then wiped over with an aqueous solutioncontaining 8% of dextrin, 1% of phosphoric acid, and 1% of formaldehyde,and then inked with greasy ink.

The diazo compound of Formula 1 0 is prepared by reacting 2.4 mols ofnaphthoquinone-(1,2)-diazide-(2)- S-sulfochloride with 1 mol ofN,N-di-(p-toluene-sulfonyl)-p-phenylene-diamine in the presence of 2.4mols of a normal caustic soda solution both reaction compounds beingfirst dissolved in dioxane. After the reaction miX- ture has beenallowed to stand for several hours, the precipitated condensationproduct is filtered oif by suction, repeatedly reduced to a fine powderby treating with a weak aqueous solution'of caustic soda, Washed withwater, and then dried. The N,N-di-naphthoquinone(1,2)- diazide (2) 5sulfonyl N,N' di (p toluene sulfonyl)-p-phenylenediamine (Formula 10)slowly darkens, when heated in a melting-point capillary tube, at atemperature above 180 C. and decomposes at 230 C.

(11) The same results as obtained in Example 10 can be had by using thediazo compound of Formula 11 in the place of the quinone diazide ofExample 10. Naphthoquinone-(1,2)-diazide-(2)-5-sulfanilide, described inExample 1, is used as star-ting material for the preparation of thediazo compound corresponding to Formula 11. Into the pyridine solutionof this diazo compound phosgene is introduced at room temperature. Thesolution is then diluted with water and acidified with hydrochloricacid. N,N'-di-[naphthoquinone (1,2) diazide- (2)-5-sulfonyl]-I,N'-diphenyl-urea is obtained in the form of a yellow powder. It istwice digested with a highly diluted solution of caustic soda and thenfiltered off by suction and washed with water. When heated, the diazocompound begins darkening at a temperature of C. and decomposes at atemperature of 260 C.

(12) 1 part by weight of the diazo compound corresponding to Formula 12is dissolved in 100 parts by volume of ethylene glycol-monomethyl ether,and this solution is used for coating a superficially roughened aluminumfoil. An image is produced on the light-sensi tive material in thecustomary manner. It is developed by wiping over with a 1% solution oftrisodium phosphate. A yelloWish-green-colored image on a clean metallicbackground is obtained, which is brieflly wiped over with a 1% solutionof phosphoric acid. This positive image, obtained from a positivepattern, can then be inked with greasy ink and be used as a printingplate.

To prepare the diazo compound corresponding to Formula 12, thenaphthoquinone-(1,2)-.diazide-(2)-5-sulfanilide is caused to react withazobenzene-4-sulfochloride analogously to the procedure described inExample 4. The N (azo-benzene 4' sulfonyl) N(naphthoquinone-(1,2-diazide-(2)-5-sulfonyl) -aniline, which is obtainedin the form of an orange-yellow powder, decomposes at a temperature ofC. It dissolves in glycol-monomethyl ether, taking on a deeporange-yellow color.

(13) A 1% solution of the diazo compound corresponding to Formula 13 inethylene glycol-monomethyl ether is applied to an aluminum foil by meansof a plate-whirler. After thoroughly drying the layer side, the foil isexposed to light behind a positive transparent pattern, and a distinctlyvisible image, which is colored a yellowish green is produced. It isdeveloped as a positive by wiping over with a 5% solution of disodiumphosphate. The developed foil is briefly rinsed with water, and theimage side is then wiped over with an aqueous solution containing 8% ofdextrin, 1% of phosphoric acid and 1% of formaldehyde. The image is theninked with greasy ink. The foil can be used as a printing plate in anyof the usual printing machines.

The diazo compound corresponding to Formula 13 is prepared by combining2.8 parts by weight of naphthoquinone-(1,2)-diazide-(2)-5-sulfochloride(in 20 parts by volume of dioxane) with 1.86 parts by weight ofphthalimide-potassium (in 7 parts by volume of water). After thebrownish-yellow-colored solution has been allowed to stand for about oneday in a cool place, the yellow-orangecoloredN-phthaloylnaphthoquinone-(1,2) diazide (2)- S-sulfonamide correspondingto Formula 13 separates in the form of crystals. The sulfonamide isinsoluble in diluted soda lye. When heated in a capillary tube, the newcompound begins to darken at a temperature of 210 C. and decomposes at245 C.

(14) Analogously to the method indicated in Example 1, printing platesare produced by using the diazo compound corresponding with Formula 14.N,N-di-[naphthoquinone (1,2) diazide (2) 5 sulfonyl]-p-phenetidinedecomposes slowly, when heated in a capillary tube, and chars at atemperature of 265 C.

(15) Analogously to the process described in Example 13, images areproduced on an aluminum foil that is sensitized with a diazo compoundhaving the Formula 15, and are developed for the purpose of obtainingprinting plates:

The diazo compound of the Formula 15 is produced by dissolving indioxane 2 mols of naphthoquinone-(1,2)- diazide-(2)-4-sulfanilide andadding to this solution, at normal temperature, first 2 mols ofn-caustic soda followed by 2 mols of 1,3-benzene-disultochloridedissolved in dioxane. After standing for a short period of time a solidbody of yellow-brownish color crystallizes out from the reactionmixture. The chemical constitution of this solid is illustrated byFormula 15. Recrystallized from glacial acetic acid, the compound onheating in a capillary tube starts sintering at 190 C. and decomposingat 220 C., after previous dark-coloration.

(16) 1.3 parts by weight of naphthoquinone-(1,2)-diazide (2)-5-sulfonicacid-methylamide (which melts at 154 C. under decomposition) aresuspended in 25 parts by volume of dioxane and then caused to dissolveby adding 3 parts by volume of 2-n-caustic soda solution and 5 parts byvolume of water. 1 part by weight of l-naphthoic acid chloride in 5parts by volume of dioxane is quickly added to the solution at atemperature of about 3 10 C., and the mixture is then left standing for2 hours.

When the reaction solution is poured into ice water, the reactionproduct separates in the form of an oil. The oil is separated from thewater, and, when mixed with some methanol, it decomposes to acrystalline mass. After recrystallization from ethanol, it represents ayellow diazo compound which decomposes at 149-150 C. and corresponds toFormula 16.

A 1% solution of the diazo compound corresponding to Formula 16 inethylene glycol monomethyl ether is coated on a roughened aluminum foilby means of a plate-whirler. The layer thus formed is first dried withwarm air, and then for a short time at a temperature of 8090 C. Thelight-sensitive foil is exposed to light under a positive transparentpattern. A 5% disodium phosphate solution is used for the development ofthe exposed foil. The developed foil is then rinsed with water and wipedover with a 1% phosphoric acid. The positive image ob tained of thepattern is inked with greasy ink, and the foil is used as a printingplate for the production of copies.

(17) To a solution of 1.25 parts by weight of l-chloro-4-nitrobenzene-2-sulfonic acid methyl amide in 10 parts by volume ofdioxane, first a mixture of 3 parts by volume of an 8% caustic sodasolution and 5 parts by volume of water; then immediately thereafter, asolution of 1.35 parts by weight ofnaphthoquinone-(1,2)-diaZide-(2)-5-sulfochloride in 10 parts by volumeof dioxane is added while the temperature is kept at about 10 C. Thereaction mixture is left standing in a refrigerator, and thecondensation product crystallizes out. For purification, thecondensation product is recrystallized from glacial acetic acid. Thediazo compound, which corresponds to Formula 17, forms lemon-yellowneedles which decompose at a temperature of 147-148 C.

1 part by weight of the diazo compound corresponding to Formula 17 and0.2 part by weight of an alkali-soluble non-hardenable formaldehydephenol resin are dissolved in parts by volume of ethyleneglycol-monomethyl ether, and the solution is coated onto a roughenedaluminum foil by means of a plate-whirler. After drying, thelight-sensitive foil is exposed to light under a transparent positivepattern. Development of the exposed foil with a 1% trisodium phophatesolution leads to a positive image, which is treated with a 1%phosphoric acid, and then inked with greasy ink. By means of thisprinting plate, copies can be printed.

(18) A solution of 2.6 g. ofnaphthoquinone-(1,2)-diazide-(2)-5-sulfochloride in 10 cc. of dioxane isadded at room temperature to a solution of 1.83 g. of(o-sulfobenzoic-acid)-imide (saccharin) in a mixture of 15 cc. ofdioxane and 2.5 cc). of water. While heating the reaction mixture toabout 50 to 55 C., 16 cc. of a 10% soda solution are slowly added to themixture. After half an hour the reaction mixture is allowed to coolwhereby part of the yellow condensation product precipitates. It isdrawn 01f, washed first with a 5% sodium hydroxide solution, then withwater and dried at 50 C. By recrystallization of the condensationproduct from dioxane, yellow colored crystals are obtained whichdecompose at about 255 C. The diazo compound thus formed corresponds toFormula 18.

A 2% solution of the diazo compound corresponding to Formula 18 inglycol monomethyl ether is coated onto a roughened aluminum foil bymeans of a plate-whirler and well dried on the foil. Exposure of thelight-sensitive foil is effected under a transparent positive pattern.The exposed foil is developed with a 5% solution of disodium phosphateand a positive image is obtained. The foil is then washed with water,treated with a 1% phosphoric acid, and inked with greasy ink, whereuponit is ready for printing.

(19) To a solution of 1.7 parts by weight ofnaphthoquinone-(1,2)-diazide(2)-5-sulfonic acid benzylamide in 10 partsby volume of dioxane there are successively added, while shaking andkeeping the temperature at about 10 C., 8 parts by volume of a 2.7%caustic soda solution and a solution of 1 part by weight of l-naphthoicacid chloride in 10 parts by volume of dioxane. The reaction mixture isleft standing for 2 to 3 hours and is then poured into ice water. Anoily prduct separates which is treated with cold methanol after thewater is removed and decomposes into a crystalline mass. Byrecrystallizing from an ethyl acetate/ gasoline mixture yellow coloredcrystals are obtained which decompose at 163 to 165 C. This diazocompound corresponds to Formula 19.

A 1% solution of the diazo compound corresponding to Formula 19dissolved in a mixture of dimet-hyl formamide and ethyleneglycol-monomethyl ether (1:3) is coated on a roughened aluminum foil bymeans of a platewhirler and dried for 5 minutes at a temperature of 9013 C. After exposing the light-sensitive foil under a positivetransparent pattern, the exposed layer is developed by means of a 0.25%trisodium phosphate solution. A positive image is obtained which isfirst wiped over with a 1% phosphoric acid solution, to which some gumarabic and/ or formaldehyde may be added, and then inked with greasyink. The foil may now be used for printing copies. This application is adivision of application Serial No. 517,086, filed June 21, 1955, whichis, in turn, a continuation-in-part of application Serial No. 325,446,filed December 11, 1952, and now abandoned.

What is claimed is: 1. A compound having the formula DS;N

R1 in which D is an ortho-quinone diazide radical, Y is selected fromthe group consisting of SO and CO radicals, R is selected from the groupconsisting of aryl and amido groups, R is selected from the groupconsisting of alkyl and aryl groups and groups which together with Rfrom a heterocyclic ring.

2. A compound having the formula SOz-R DSO2N R1 in which D is anort-ho-quinone diazide radical and R and R are aryl groups.

3. A compound having the formula COR DSO2N in which D is anortho-quinone diazide radical, and R and R are aryl groups.

4. A compound having the formula CO-R D-SO2N in which D is anortho-quinone diazide radical, R is an amido group, and R is an arylgroup.

5. A compound having the formula /YR DSO2N in which D is anortho-quinone diazide radical, Y is an SO group, and R together with N,Y, and R forms a heterocyclic ring.

6. A compound having the formula /YR DSO2-N\ in which D is anortho-quinone diazide radical, Y is a CO- group, and R together with N,Y, and R forms a heterocyclic ring.

7. A compound having the formula :X S02-R SO -N in which X and X; areselected from the group consisting of N and 0 and are different, and Rand R are aryl groups.

8. A compound having the formula 0 CH: ll

so2 N so,

9. A compound having the formula CH3 1 SO:N

10. A compound having the formula 0 0 H H Nam was.

s0i 'N-S0i 40 11. A compound having the formula Na: a

SO-NSO 12. A compound having the formula 0 o H II solNoo-Ns02 13. Apresensitized printing plate comprising a base material having a coatingthereon comprising a compound having the formula in which D is anortho-quinone diazide radical, Y is selected from the group consistingof 40 and CO radicals, R is selected from the group consisting of aryland amido groups, R is selected from the group consisting of alkyl andaryl groups and groups which together with R form a heterocyclic ring.

14. A presensitized printing plate comprising a base material having acoating thereon comprising a compound having the formula SO2R DSO1N R1in which D is an ortho-quinone diazide radical, and R and R aresubstituted aryl groups.

15. A presensitized printing plate comprising a base material having acoating thereon comprising a compound having the formula COR D-SOz-N R1in which D is an ortho-quinone diazide radical, and R and R are arylgroups.

16. A presensitized printing plate comprising a base material having acoating thereon comprising a compound having the formula CR DSO2N R1 inwhich D is an ortho-quinone diazide radical, R is an amido group, and Ris an aryl group.

17. A presensitized printing plate comprising a base material having acoating thereon comprising a compound having the formula Y-R DSOzN R1 inwhich D is an ortho-quinone diazide radical, Y is an -SO group, and Rtogether with N, Y, and R forms a heterocyclic ring.

18. A presensitized printing plate comprising a base material having acoating thereon comprising a compound having the formula Y-R DSO2N R1 inwhich D is an ortho-quinone diazide radical, Y is a 'CO group, and Rtogether with N, Y, and R forms a heterocyclic ring.

19. A presensitized printing plate comprising a base material having acoating thereon comprising a compound having the formula in which X andX are selected from the group consisting of N and O and are difierent,and R and R are aryl groups.

20. A presensitized printing plate comprising a base material having acoating thereon comprising a compound having the formula l 6 21. Apresensitized printing plate comprising a base material having a coatingthereon comprising a compound having the formula I I I S02-N 22. Apresensitized printing plate comprising a base material having a coatingthereon comprising a compound having the formula 0 O H II m 1 i 23. Apresensitized printing plate comprising a base material having a coatingthereon comprising a compound having the formula v 24. A presensitizedprinting plate comprising a base material having a coating thereoncomprising a compound having the formula 25. A process for developing aprinting plate which comprises exposing to light under a master a platehaving a compound thereon of the formula in which D is an ortho-quinonediazide radical, Y is selected from the group consisting of SO and -COradicals, R is selected from the group consisting of aryl and amidogroups, R, is selected from the group consisting of alkyl and arylgroups and groups which together With R form a heterocyclic ring; tothereby form a decomposition product in the light struck areas and re- 17 moving the decomposition product by treatment with a weakly alkalinesolution.

26. A process for developing a printing plate which comprises exposingto light under a master a plate having a compound thereon of the formulaD-SOz-N R1 in which D is an ortho-quinone diazide radical and R and Rare aryl groups; to thereby form a decompositoin product in the lightstruck area and removing the decomposition product by treatment with aweakly alkaline solution.

27. A process for developing a printing plate which comprises eXposingto light under a master a plate having a compound thereon of the formula1 in which D is an ortho-quinone diazide radical, and R and R are arylgroups; to thereby form a decomposition product in the light struckareas and removing the decomposition product by treatment with a weaklyalkaline solution.

28. A process for developing a printing plate which comprises exposingto light under a master a plate having a compound thereon of the formula1 in which D is an ortho-quinone diazide radical, R is an amido group,and R is an aryl group; to thereby form a decomposition product in thelight struck areas and removing the decomposition product by treatmentwith a Weakly alkaline solution.

29. A process for developing a printing plate which comprises exposingto light under a master a plate having a compound thereon of the formulaR1 in which D is an ortho-quinone diazide radical, Y is an -SO group andR together with N, Y, and R forms a heterocyclic ring; to thereby form adecomposition prodnot in the light struck areas and removing thedecomposition product by treatment with a weakly alkaline solution.

30. A process for developing a printing plate which comprises exposingto light under a master a plate having a compound thereon of the formulaR1 in which D is an ortho-quinone diazide radical, Y is a CO- group, andR taken together with N, Y, and R forms a heterocyclic ring; to therebyform a decomposition product in the light struck areas and removing thedecomposition product by treatment with a weakly alkaline solution.

31. A process for developing a printing plate which comprises exposingto light under a master a plate having a compound thereon of the formulain which X and X are selected from the group consisting of N and O andare diiferent, and R and R are aryl groups; to thereby form adecomposition product in the light struck areas and removing thedecomposition product by treatment with a weakly alkaline solution.

32. A process for developing a printing plate which comprises exposingto light under a master a plate having a compound thereon of the formulaS O2N CllHa to thereby form a decomposition product in the light struckareas and removing the decomposition product by treatment with a Weaklyalkaline solution.

34. A process for developing a pninting plate which comprises exposingto light under a master a plate having a compound thereon of the formula0 0 II N m I l to thereby form a decomposition product in the lightstruck areas and removing the decomposition product by treatment with aWeakly alkaline solution.

35. A process for developing a printing plate which comprises exposingto light under a master a plate having a compound thereon of the formula0 II H w w to thereby forma decomposition product in the light struckareas and removing the decomposition product by treatment with a weaklyalkaline solution.

37. A compound having the formula 0 0 u u w w 38. A compound having theformula 39. A compound having the formula SOr-N-SO;

40. A compound having the formula 41. A compound having the formula ISO:

42. A compound having the formula H: CH3

43 A compound having the formula 44. A compound having the formula 45. Acompound having the formula 0 0 II II m SOr-N-SO:

21 22 46. A compound having the formula 49. A compound having theformula i? i 3 :N3 N2: 5 N2:

SOzN-S0 SOg-N-SO2 x S Oa-N 50. A compound having the formula 47. Acompound having the formula A u dha th f I la 51. A presensitizedprinting plate according to claim compo n W g e O m 13 in which thecoating includes an alkali-soluble resin. 52. A process according toclaim 25 in which the com- N 25 pound is in admixture with analkali-soluble resin.

01 References Cited in the file of this patent JH3 FOREIGN PATENTSSOPPFOZS 30 510,563 Belgium Apr. 30, 1952 516,129 Belgium Dec. 31, 1952930,608 Germany July 21, 1955

13. A PRESENSITIZED PRINTING PLATE COMPRISING A BASE MATERIAL HAVING ACOATING THEREON COMPRISING A COMPOUND HAVING THE FORMULA